Are there issues with transmitting objects over Unix sockets between processes? How to eliminate serialization?

When passing objects between processes via Unix sockets in Python, serialization is necessary because sockets transmit bytes, not objects directly. Typically, modules like pickle or json are used for serialization. However, serialization can be time-consuming and resource-intensive.

To avoid explicit serialization, you can use the multiprocessing module with its mechanism for sharing objects through multiprocessing.Connection or multiprocessing.Queue, which internally use serialization but do so transparently for the user.

If you need to transfer objects without serialization, you can use shared memory or memory-mapped files (mmap), where both processes work with the same memory block. In Python 3.8 and later, there is the multiprocessing.shared_memory module, which allows creating and using shared memory.

Example of using shared memory:

from multiprocessing import shared_memory
import numpy as np

# Create a numpy array
arr = np.array([1, 2, 3, 4])

# Create shared memory and copy data into it
shm = shared_memory.SharedMemory(create=True, size=arr.nbytes)
shared_array = np.ndarray(arr.shape, dtype=arr.dtype, buffer=shm.buf)
shared_array[:] = arr[:]

print('Shared memory name:', shm.name)

# In another process, connect to shm.name to access data without serialization

# After use
shm.close()
shm.unlink()

Thus, to avoid serialization, it is recommended to use shared memory or specialized IPC mechanisms that allow direct data exchange in memory.